Water well experts

[bdog]

I am drilling a well on my place for some light irrigation such as watering our pecan trees and maybe a gun or two to water one field and filling a fish pond. We are permitted for and expect to get 70 GPM at around 150 feet. Met with the driller today and he is drilling a 17" hole and setting 8" casing with a gravel pack. The driller seems very knowledgeable and has drilled a lot of wells in the area but is asking me a lot of questions on how I want things and frankly I don't really know what he is talking about.

I guess there a variety of different types of pumps (I have 220 single phase) and types of things they can do at the surface. He was talking about if I wanted a pad or a sleeve, if I wanted a pressure tank, and some other things I don't remember. I trust the guys judgement on setting this up but I am looking for any advice I can get on things to ask for or certain ways to do it.

Basically I would like to run the appropriate sized pipe (2" maybe) underground to by the pond and several risers that I can connect to for watering things.

 

[Oldgreybear]

Please tell me where in texas you are and who you found willing to drill a water well. I have been looking for over a year and can't find a driller willing to drill a shallow well. I am looking for the same things you were, except I want to put a windmill (Aeromotor type) on it.
Thanks
Bo

 

[bdog]

I am in the Lubbock area. Tons of water well drillers here. I talked with probably a half dozen getting prices before I made a choice. Wells are not cheap though I figure after the drilling, pump, etc I will be out close to 10k but my well should flow over 100,000 gallons a day if I wanted it to.

 

[Magicman710]

Sounds like you guys have to drill wells differently out in Texas. Here, in coastal plain Georgia, a 70GPM well would require only a 6" hole. Your static water level at 150 feet is very similar to ours, though.

To get 70GPM you are likely going to get a 7.5HP pump. Single phase will run that, you have no issue with your power supply. If you wanted more GPM (100-200) you'd want to have three phase or at least a three phase converter, since three phase pumps run more efficiently (less power usage).

I'm not sure what he means by "sleeve or pad". I'm assuming by "pad" is he meaning a concrete pad to seal around the top of the casing and provide a platform for the tank, if you get one.

Depending on how you set up your irrigation, a pressure tank may be needed or not needed. A pressure tank is going to give you a lot more leeway in varying GPM applications. It allows you to maintain a fairly steady pressure whether the pump is running or not. If you don't use a tank, you have to use ALL of the water (70 gpm!) the well is producing, because the pump can either be ON or OFF. On is producing 70gpm, off is producing nothing. The tank lets you use water as you need it, anywhere from 1 GPM to 70GPM. The only thing to watch for is how often the pump has to cut on and off with a pressure tank. Optimally, the pump will run continuously (if rated to do so) in a high application load like irrigation. Otherwise, the pump needs to cut on no more than every 10 minutes or so. You will reduce the life of the pump otherwise.

So, in other words, if you set up your pecan irrigation system to use roughly 60-65GPM, you don't have to use a tank. If you think that down the road you are going to use the well for watering with a sprinkler or something, you will want to have a tank.

2" pipe should be fine for the uses you describe as well.

 

[flusher]

Here are some photos showing my well installation in May 2005.



Well is 154 feet deep. Pump is 1.5 hp at 120 ft. Water level in well was 53 ft. Well blew out at over 100 gpm.
Get 30 gpm with that Franklin pump. 30 gal pressure tank set at 65 psi.

Poured the concrete slab myself.

Good luck

 

[flusher]

Forgot to add that the cost was $5500.

 

[Xfaxman]

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Depending on how you set up your irrigation, a pressure tank may be needed or not needed. A pressure tank is going to give you a lot more leeway in varying GPM applications. It allows you to maintain a fairly steady pressure whether the pump is running or not. If you don't use a tank, you have to use ALL of the water (70 gpm!) the well is producing, because the pump can either be ON or OFF. On is producing 70gpm, off is producing nothing. The tank lets you use water as you need it, anywhere from 1 GPM to 70GPM. The only thing to watch for is how often the pump has to cut on and off with a pressure tank. Optimally, the pump will run continuously (if rated to do so) in a high application load like irrigation. Otherwise, the pump needs to cut on no more than every 10 minutes or so. You will reduce the life of the pump otherwise.
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Not true the flow rate will determine the RPM of the pump. the AC current draw of the pump motor is directly proportional to the water flow. Low gallons per minute = low current, high gpm = high current. Watch the Amp gauge on this Website:Cycle Stop Valves, Inc.

Link to my pump monitor thread: http://www.tractorbynet.com/forums/rural-living/271589-water-well-pump-monitor-2.html#post3233411

 

[buickanddeere]

Supply single phase to a VFD that varies the frequency of three phase power to the well pump. Flow will be adjustable. Using a pressure tank the system can supply water without cycling the pump on off on off on off on off . The three phase well pump motor uses less electricity per Gallon of water than single phase . Three phase Motor is also simpler and more reliable than a single phase motor and starter.

 

[PILOON]

For sure you want a tank. Think of it as an accumulator. If the tank is inflated to 60 PSI you will get a constant 60 at the nozzles all the time. The pressure switch will only activate the pump when the tank pressure falls below the low setting (like 40psi) all while maintaining the high pressure.
This way the pump will be off (resting) lots of the time.
Most wells today are drilled and use a 6" pipe which is required in soil layer but not in rock. Usually they will drill much deeper than the water table so as to create a reservoir. For potable water they pour a concrete slab around the pipe in order to seal the well from surface water intrusion that could carry nasty stuff.
When it comes to pumps, they are sized based on depth, pipe size and GPM you need.
In critical situations elbows, line size etc are all calculated as friction is also a factor.
Once drilled and the source GPMs are known you then can select the pump that matches the supply and your requirements.
(No use having a pump that exceeds the supply as then you get into major costs to control the pump. Like monitoring and variable controls etc)
By the way, most pumps are sized for 1 1/4" outlet and most household installations use 1" pipe.
The common line is a blue HD poly B line that is very durable.

Google and locate well pumps (Jacuzzi, Grunfoss are a couple) and you'll get all sorts of info as to GPM, lift pressure etc etc.

About $1000. would be a typical budget for pump etc, with a well going $18.00/ft with some travel/set up charges etc. (Cdn$)

Good luck, hope I helped a bit.

Just went thru the exercise last month here in Quebec.
Had most quotes @ $11-$12,000 range but persisted 'til I got er done for $3500.(we had water at 90 ft and he added 100 more for a reserve and we set the pump at 180 ft. Tests showed 20 GPM.. We used 3/4 12GPM pump and 1" line.

 

[ultrarunner]

Here are some photos showing my well installation in May 2005.

View attachment 422279View attachment 422280View attachment 422281View attachment 422282View attachment 422283View attachment 422284

Well is 154 feet deep. Pump is 1.5 hp at 120 ft. Water level in well was 53 ft. Well blew out at over 100 gpm.
Get 30 gpm with that Franklin pump. 30 gal pressure tank set at 65 psi.

Poured the concrete slab myself.

Good luck

Looking at similar and prices are 25k and up... well drillers are booked solid here and basically can name their price... good thinking to get it done when you did.

 

[buickanddeere]

Can't imagine a well head, tank and pipes outside. They would be frozen and split here between October and May.

 

[bdog]

Thanks for the replies so far.

The drillers came today and dug their mud pit. They made it 15' deep and about 6' wide and 30' long. It is a good sized hole for sure. Hopefully if the weather cooperates they will move the rig in tomorrow.

Regarding the pressure tank will they work properly with this high of flow and how large do they need to be? My house well might be 5 GPM and the pressure tank is probably 30 gallons? It is pretty good sized. Using that ratio for a 70gpm well would I need a 420 gallon pressure tank?

 

[TomSeller]

Can't imagine a well head, tank and pipes outside. They would be frozen and split here between October and May.

Right, but not in Sacramento. Amazing the differences in climate the US has.

 

[ultrarunner]

We have all are hose bibs in copper outside and the water meters are just below grade in my part of CA...

 

[Egon]

You might want to consider pressure tank for the domestic potable water and just bypass it for the irrigation system.

At 30 gal./min. The pressure tank may be just a little bubble in the line that hasn't the volume to really do anything.

 

[buickanddeere]

Nobody ever installed a pressure tank that was too large on a water supply system. Properly plumbed with a minimum of bends and corners . The pressure tank will also reduce pipe work stress by absorbing water hammer. Some systems need more than one pressure tank.

 

[jaydee325]

For those of you who like numbers, or are engineers, or just like this stuff:

Pump Laws Review and Equations - Engineers Edge

Have fun!:thumbsup:

 

[flusher]

Can't imagine a well head, tank and pipes outside. They would be frozen and split here between October and May.

Hardly ever freezes here on the North Sacramento Valley floor. Had one freeze up--ice in the stem of the WOG valve that shuts off the water to the house, shop, landscape irrigation. Just wrapped the valve in fiberglass--problem solved.

 

[TheGoose]

How big is your pump and what is your desired gallons per minute flow? Your tank needs to be sized to give you a one minute draw down. In other words, if you have a 30 GPM pump your tank needs to be big enough to let out 30 gallons before the pump comes on.

 

[bdog]

How big is your pump and what is your desired gallons per minute flow? Your tank needs to be sized to give you a one minute draw down. In other words, if you have a 30 GPM pump your tank needs to be big enough to let out 30 gallons before the pump comes on.

It will likely be a 7.5 HP pump and we are shooting for 70 GPM. They finished drilling today at 144' and they have set 8" casing. I think the plan is to do a flow test tomorrow. Once we know what it will flow we will decide for sure on the pump size.

So you are saying if I have a 70 GPM pump I will need a 70 gallon tank?

Just to clarify I am not running my house off this well. I have a separate well for that. This one will be used to fill and maintain a pond and possibly some light irrigation.